This paper presents an update on the baryon abundance from big bang nucleosynthesis (BBN) in early 2024. The study focuses on the derived baryon abundance and its relation to light element abundances, particularly deuterium and helium. The results show that the baryon abundance is determined with high precision, with values of Ω_bh² = 0.02218 ± 0.00055 using PDG-recommended light element abundances in ΛCDM, and Ω_bh² = 0.02196 ± 0.00063 when considering additional ultra-relativistic relics (ΛCDM + N_eff). These values are derived from the PRyMordial code, which allows for a conservative estimate by marginalizing over nuclear reaction rates. The study also finds that the effective number of neutrino species, N_eff, is constrained to ΔN_eff = -0.10 ± 0.21 based on light element abundances alone. The paper discusses the sensitivity of the baryon abundance to the assumed deuterium burning rates, which are influenced by both theoretical ab-initio calculations and experimentally-determined rates. The results show that the baryon abundance is tightly connected to the deuterium abundance, with higher baryon abundances leading to higher deuterium burning and lower final deuterium abundance. The final helium abundance is also closely related to the baryon abundance, with higher baryon abundances leading to more helium production. The study also addresses the helium anomaly, where a recent measurement from the EMPRESS survey shows a lower helium abundance than other measurements. This discrepancy is discussed in terms of its impact on the derived baryon abundance, with the results showing that the EMPRESS measurement is an outlier and not compatible with the standard BBN codes. The paper concludes that the baryon abundance is well constrained by BBN, and that further laboratory measurements of deuterium burning rates will be crucial for improving the accuracy of the baryon abundance determination.This paper presents an update on the baryon abundance from big bang nucleosynthesis (BBN) in early 2024. The study focuses on the derived baryon abundance and its relation to light element abundances, particularly deuterium and helium. The results show that the baryon abundance is determined with high precision, with values of Ω_bh² = 0.02218 ± 0.00055 using PDG-recommended light element abundances in ΛCDM, and Ω_bh² = 0.02196 ± 0.00063 when considering additional ultra-relativistic relics (ΛCDM + N_eff). These values are derived from the PRyMordial code, which allows for a conservative estimate by marginalizing over nuclear reaction rates. The study also finds that the effective number of neutrino species, N_eff, is constrained to ΔN_eff = -0.10 ± 0.21 based on light element abundances alone. The paper discusses the sensitivity of the baryon abundance to the assumed deuterium burning rates, which are influenced by both theoretical ab-initio calculations and experimentally-determined rates. The results show that the baryon abundance is tightly connected to the deuterium abundance, with higher baryon abundances leading to higher deuterium burning and lower final deuterium abundance. The final helium abundance is also closely related to the baryon abundance, with higher baryon abundances leading to more helium production. The study also addresses the helium anomaly, where a recent measurement from the EMPRESS survey shows a lower helium abundance than other measurements. This discrepancy is discussed in terms of its impact on the derived baryon abundance, with the results showing that the EMPRESS measurement is an outlier and not compatible with the standard BBN codes. The paper concludes that the baryon abundance is well constrained by BBN, and that further laboratory measurements of deuterium burning rates will be crucial for improving the accuracy of the baryon abundance determination.